Hello folks,

I am pleased to announce http://passguardian.com. This is a a client-side (browser) implementation of Shamir's threshold secret sharing scheme. In a nutshell, this helps safeguard your secrets by breaking them into cryptographically-secure "shares". A user-defined threshold number of shares are required to reconstruct the original secret. The secret cannot be derived from individual shares.

It is currently hosted on GitHub (https://github.com/amper5and/secrets.js/tree/gh-pages). PassGuardian.com uses the open-source secrets.js (https://github.com/amper5and/secrets.js) implementation of Shamir's sharing scheme. The finite field used in the online version is 8 bits, allowing up to 255 shares.

All computations are performed client-side, in your browser, without transmission of any secrets or shares to the server. Stand-alone and mobile versions are being considered if there is interest.

Currently you can share text and hexadecimal strings. Support for files (drag-and-drop) and QR codes is in development.

For example, to split your private key, paste the hexadecimal version into the input box, select "hexadecimal", select the number of shares and the threshold, then click "split."

This is a work-in-progress, and hopefully I will be able to expand it and add more Bitcoin-specific features over the next couple of weeks.

Feedback, bug reports, suggestions, and criticisms are all very welcome.

Regards,
amper5and